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I’m interested in developing some low velocity/pressure loads using pistol powders in 223 & 7.62x39. Something that would be useful as a small game load that wouldn’t require the burden of a second rifle while afield. I’ve read that brass used for such loads should be kept separate from brass used for full power loads. I’m not clear on exactly why. Would using fire formed and neck sized brass remedy the situation? Any information provided would be greatly appreciated.
The firing pin strike on the primer will shorten the case after a few firings. Jamming the bullet into the rifling a bit will keep the cartridge where it belongs against the bolt face. Rifle with claw extractors such as the military Mausers help.
Thanks for the reply fa38. Sounds as if limiting the number of low pressure cycles might allow for longer case life. The arms I will be loading for are semiautomatic and the bullets are light. Loading into the lands may not be possible. Is there a preferred method for observing the case length limit?
I made some 38 wax bullet cases and to differentiate between them and standard ( Flash holes were also opened up to .100 dia) I ground a drill bit with a .100 pilot .150 long and the correct dia for large pistol primers. When I opened up the flash holes I also changed them to large primer pockets. These cases now wont hold the standard small pistol primer if they get mixed in with my regular brass.
the one thing you can do to extend the life of your low velocity brass and keep shoulders in right place is every 2-3 loadings fire it with a mid range load to fire form shoulders back to place. The 223 wouldn't have much rim left converted to large primers but 7.72X39 could be sleeved to small rifle pockets. The other thing that might be done would be to press a very light straight knurl into the head just in front of the extractor groove similar to the 308 NM ammo from Lake city. Thus would be permant and stand up to firing and polishing unlike markers or coatings. Ive seen small pipe cutters set up for this. the rollers are retained and the cutter is replaced with a straight knurl roller. A simple wood collet handle is made to hold case so that the roller set against it is correctly positioned and tension set and a couple turns made.
Thanks for the reply country gent. You have some very interesting and well thought out solutions for such loading. I like the idea of converting to a large primer pocket to differentiate your wax load brass.
I discovered Hornady makes a headspace comparator bushing set that would allow an exact measurement of the cases. When they get close to the s.a.a.m.i. minimum, I would simply run a mid-range load as you suggested. Thank you for your insight.
Are you using these two calibers in a semi-auto rifle or bolt gun? Loads for a semi should be full length resized always...neck sizing is used when the brass is fired in the same (bolt) gun all the time, and as a result the brass lasts much longer.
I keep my brass segregated. All cast load brass is in separate containers and clearly labeled. For regular full power loads I use only factory new brass or cases that I have carefully noted the number of loadings. The odd thing is, the full power brass is hardly used any more since I got into cast!